SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c2f1ff0f1a482812ccd9eca6594c0206c0d48da6d09d1ca7eb09891dd807542' 
  AND token = 'cc5SYnl1Dn6kTuUIoIRSCZoKogq+J9BmH8Zy/eqE14Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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