SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec2073216b38fd7cc303099adfc808bc918667f4ab28388fc74e252d2874cc0d' 
  AND token = 'zXjfFP+/C95igFYXplkrEhEBlVasa4JJGjbSf0gr2IQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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