SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afc734f91d7237ff270573340f73d1aa7291d41adef8ed74cedaeaab8d7bf7a5' 
  AND token = 'cva5RcurHXOp3kxp+XlCTvAbtoQZ5YVmcSlgOcou2mU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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