Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a421eee6caaecb54c695025f15d1f12dc48a5ef6a0476b7ac9e8271e9da79178' 
  AND token = 'Ga9JtPR2SoO3FRLA9+1R8fsrwtFNXZ9ssEGRPXgTPUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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