SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c5ac0c39e866d47becb1df24435d738e35f9f16abfe9be25d328465584a4731' 
  AND token = 'P/RKkRsX3JQzA/D24Dom1bvL6d8AtADKp8YyTfLmqc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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