SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e069b04bfae721401edfae2cfbe5bf7c1a8bf3926a099613d864f580ffd696a' 
  AND token = '/2QB0RhghgfvVMRDtJVGiKZDciUFYC1cjDNlzUQMia0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}