SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63a8809ad70b0dc92b28d35e1714173d8f12dd4d66bb7d78a6bc1425b7a9c220' 
  AND token = 'MMPQ1IDbPj4uHJmNFOhHwetpYOHJpMYw/xT10Et40UA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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