SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe9ead8ba485fef024860366428247519166d01d7c5aa4f64dc89c60536eb2c1' 
  AND token = 'u+xDUwFk6qe7xdqdi+MkoPNnOvV/vI1mIvRVtJsppE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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