SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac913cce84e1558e41ed54c335105900b8601ac2f4776bd5915483f976b8afb2' 
  AND token = 'j0M6ISzmZG4Iv0U4gGg3QkgwdyYAO8n2psEMXwzwdwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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