SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c37978df1fe6ce729b7200d361909a7d2a705142f7c14ab234b5d39cf4b7ee34' 
  AND token = 'QvDDUf3gOkhX/zVrH0Uhkaw8ckxv3gwl+PuQZxCYYBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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