SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e16f07a081b5872344eb0122e7338059ee00000a3677988ad18477aceddbe66' 
  AND token = 'ottzhfvX/SeZx8NhnfVsEjQnqjHTkde5wknEBSJ88Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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