SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e953298668d466af73504215c54735eb45aeef64bac6e39a5869d4844ca2e2a6' 
  AND token = 'k75PNJfeTl65BazwhMblV9UomyU3f8s49jrugjVv/Gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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