SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '778eae8df90e8a52807ec2ba8601ec4216d03afa86e468ed286761d58a81e489' 
  AND token = 'a3BBE/GnligL/nsIVuM+feBTJR9CnqGQ4cyJlvw18zM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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