SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79db07bec315562934f3c43ce89d81af97507b34cc76fecda722aaa853c8528' 
  AND token = 'TQbpYgq70Ce0eMUWGf4sMhAyzh9VsNluLus7+sWbFng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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