SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef090067ba9dd82e44fc544ab73def1b9acc9dbb56730fb44eec48822823bce5' 
  AND token = 'Kch37+sDVEq/0DERqf4hBGYBBzNFsy4IG9YT1i+yQoE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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