SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '74d1ccbf26eca940064f0a1d761bf3673af067584c5a4a4fa38e6fdf3fd5ec57' 
  AND token = 'ZKYvvdstJSBk2TOxtbdSfNoV+3EFC3ASJu4r+urvZoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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