SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd64c1f786d3c19764cc9287e1dce750614aee3ce9d838efca888bdc8a43d0fb2' 
  AND token = 'CMOoVQOFCmrXK/RlSzm7/vx0oQXodaMyjylzyE0KxFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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