SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64195987f230430c460cb6ee240eab8cb3da6535d39959fed362fe2c3b13a4bb' 
  AND token = 'aVQB+KIuCIgTAZXWpqtEMnDxJj+kJNDDmD4d8+Z5Ltw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00074

JSON explain

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