SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87af399ad6e589d25d3cce302301d2f45a3edaef992fa38f68ff03488713b71c' 
  AND token = 'iBmMRPGqUDYL5Bju14uBdX/kjFZZFkwf8KSm/ds5htc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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