SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7385747f61f2c815bcfcad80f30ea0b7a91e74fc8c8df9a5b78cf847ae99742' 
  AND token = 'HJMtS7F2qnqFtwB3mOR8TM0IzFnU/VNUGp5uCZsDkvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}