SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c44604f20fd6bf642483ecac7046164c4ddcd799765cad6fad63f6eb31649734' 
  AND token = 'TYS/FIXCo2iPcjPz+ExV4aTeQ/WYsGNOhZDLtgTDMm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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