SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e1b61edd8495d67dff016d35870d3fc85bd770de8d9dadba978aa3e4af456199' 
  AND token = 'jLblhDFK6ZYzKwjd+Slbd2j6NOlbIsAz+zKFngAhqz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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