SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f16fc2e86d5fdae8654e2bf6e217a5af62f064f5a04afb96e36efd919ed3f9e' 
  AND token = 'IBJmpweheNrYBI0PMLgoFniGZ2AIVxAMk31rxVc8Cgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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