SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19dc1054f028be4de42c8b0fce4db7236256c470a8c184a49260381bb4c11b69' 
  AND token = 'TgezRC71dj16ppBRGHvETONTzopIKxXVzpg3EtZeBWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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