SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b53f14a6afe5ff3e64729ccabd5fedc8aada91f09c3679abdb6f2df3f499af5f' 
  AND token = 'yLbFK1yurATvWss4Da22my+JcFk4CmZ3+j+iFR+AUYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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