SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f2e7bbb6d4f8be7d562c402357d4ea0f065bac9df2498805643b0689cd07cfe' 
  AND token = 'iyUXebwLCzX+mxKENKEZMZ+2nTJ1crUhHZwwI3oLjv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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