SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f1b1192dcf6fb56ece5ed39ad9490e68b398220a55c5559a1dfcffbebe76b7e' 
  AND token = 'cJ2GnDKouYR+uHa1guq9EAR9yryg8xUF2vrHrF57/mI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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