SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8678a7d0995739047664264ffe26899f3d7993723ceb0c62cd0b1cb069c5255c' 
  AND token = 'BaFZFtHXsZO+pVfvb2H4FnqJG8S83P1XMNWqPkPIOwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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