SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '864a5c20b1768e2cb47dfe9345c3c8a97839747bc23bd62655efaa5ab7412e60' 
  AND token = '/1lLqRqds1DxPwpEg1JIy9v+OprhnPh6UAQI4pXMkm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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