SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd47c499f8b8f61baf3e47311fe33d0096abff6c07fe58a35eb47ad9ee7cabe0a' 
  AND token = 'Tf/9uAAcQm1VyCJQTLcZxvcrddIkmqDxQabecYILvB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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