SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ddc9951663d95ef3881e3eb2894fc1f2df62acb5ae8af37024fc95cf34ad1ca' 
  AND token = '4+oyVwJGJX10SIPVtXuCRo3OSpWyXahpXD/hnPofXyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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