SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bd20c7120423dfd99beaf968906bc5c4645599fccb28aef6bebe612548e131c' 
  AND token = 'BaBWRDHR1gVGHphplAB+Oj+3Vqs0TlifAvQa/Lo/qNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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