SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbf9e27a0043ae76a76b8a268480fce934f56b5837a1562ec1192c506ad78786' 
  AND token = 'ZYKpn6iqReVnxsAiWKQQoawC/smrufk98la/fkd1wCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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