SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd73efc0bb1aa08fcb1a69f6042c07f0a33cea7f5cdb8737be2843525ef399766' 
  AND token = 'QBJCZ3/1TbYdJRlI+bW6+uPld8JzXNPKVAxn9YnbJIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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