SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b13262678a6ff29352824786ef9e2f6946f0a4ad7fcfee65add0d2604581c4c' 
  AND token = 'AiBT0kPTeODfvlj0j9iOsRwQskOEeIzVNDIq0R+Sh3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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