SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f59900758c97479b886bb716fed2bccaf7b9b83024e02cff3a902c785429d67' 
  AND token = '/SryLZkDCehAYOijHDAj5CqxJ0C2F56Vqr+EASWRZ4g=' 
  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"
    }
  }
}