SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48864a7e2657ed9758dba4c3e525d03727418265d9b980b981da19105dd3b58f' 
  AND token = 'OWFEkp2bG0BUHjHPo1rOYjf6G7pCaCQYgU+VoEDUVzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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