SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67cfe7b77cfd0ebcafd628b542022c4d1731b847d78be5c656244c88b3153e55' 
  AND token = '47RIyLPopQmqUAsgYxJAKCCiNxKkOR2ohU7m9nzD508=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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