SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f2d7912f8988f79df7f8f11632220b7ba131530ce9586bca179c5158743e5d5' 
  AND token = 'RgvqaqFluhZFwktklDOR9Xv2MIkw3Pp/4A8aFhm67qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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