SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb50549fb5d62e864f83da48376361efdd8aa3d98512acdf8e8e010d0fa75102' 
  AND token = 'LGq8Fl9HCgSo9t21MRl+MOa3PPQiUN4Is4QkRqOpgro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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