SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a780da9770d9a7d2dfed98af2028f777ebc841401f4cfdfc09b3eff7805e1eba' 
  AND token = 'RWMBUOmLXSL27lelJOPzq7qkyHhfuUqi6vBeFhXgWWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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