SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd2885185c0c52b82705c86483abe4dd9a492490a3f00f3b0bb7dda5f180c2a9' 
  AND token = 'QlxeZPByp7/jpXPSFCjR1zytVn2DnyqiFlWIcbDP0wg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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