SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c44df59ba29d893797605b04c25d5d4c5126e168339024a4f745fd1a96d045' 
  AND token = 'T7enEDiRWwEKjVwOYUav/yPWoqMzbJkh0K0j4GtPfh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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