SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '649acd73350e341d25a843c704036a3d4e11fcb4ffc4a567b573ec5ebf99fafb' 
  AND token = '7qW5Spbs8WbseYhZjqcVZikXjdhhaVn+wcAmyu0mhRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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