SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea03f12cc672b74cdbfeaf036573843e576798f68324031f9c6bd51ffccb9a3e' 
  AND token = 'zovPMzkZT+nJyvTK4idPvBkYZGZqP0+vqvhTjsmh2U4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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