SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12d616724d440356731b6b6d16fcc4d5c681a72bed114abb5ac2c6196e012e23' 
  AND token = 'qPntYLpPy8t1vvi0RKk25xN9rTTkAb0Tm6vzNSujjKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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