SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '544121e692dfe841e785d31077ce622755e6c399b8975bd25bbe8ac27ac5ca0d' 
  AND token = 'QbZ4AY/EqCoQwVWuR4QH97IWs/qA3HGS3gPKF/D5PJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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