SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08925492736a2fd7c637d9433f7abf6a369fb39271e4a0ca5cdb18d8ca470ce3' 
  AND token = 'LXdpH6F1eycs8NYIy6s6Q9tXWSGEcdZfauhWi6EVtd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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