SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba69346faae685ef191f19bbe6bc73123353eb35406c5c7eb15b530055d39da3' 
  AND token = 'Tvil5rhYmNSpoMiZO5CMKCBqbsJ3Up/SgP5Da0Jxsdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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