SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a75b5f1f8b3232262df17e54b0516aeb3d4f0e330b8b63c47918398ca0aaef2' 
  AND token = '0owLUpGuGjFc8wt2ePvmxJoZ4VMcxXHhI55XgJ4MwG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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