SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '023209a0223d3ee1a11a4c581e2b11899bea6c923842b1ee3bd69537e8f1be92' 
  AND token = 'dBzriUNcLuCicix8v1wDp/eVqCqVMYB7hrpu0lpQ41U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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