SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4a57692b2e9489e2af1e29fe74eede275cf45b424ccd16e684f987c69d670c' 
  AND token = 'KLDr0dw6lmemBgutY/XJrZPjMiPbbsvN47ruwPitmNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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