SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e832d08895921f369c3a08a87f5bc360528f31604e21d1d82aed1188620bed0d' 
  AND token = '2RxNHOMjpDxPLQutaREFEya0/N2gw5kEJRQ1AvsjjzA=' 
  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"
    }
  }
}