SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d541da1879c95497db8ec199aacc6f1a22bafc36b147520d21793d29cefcbd1' 
  AND token = 'ji9dlu/sLKID7tbf9YEI7e69GC4mPW/S+2V7v4HMBBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}