SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '802538ed596114496bfc6d3c039f06fba50ee31919dafc6fc926575322446457' 
  AND token = 'bG+pMusYLg2uexeB6SukKqAhnPCiqzxG1KSI5B5+6Q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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