SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8ed9604e7aa493f427c133698d9ae19cacf2dad6547b5e7d42c684d540bbeb8' 
  AND token = 'RtJ9qrdeeEruQR7eqQZwxWM9MVxvV6PhFeQJUuv+LKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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