SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f172a9481fbcef7f9e5866f3a781506bfb4f5f03249001a17090bec8bcc608c' 
  AND token = 'jODh48KMR5LHQEpLzFmYVT1/Qqv+TR97BGZIGtB4Rz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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