SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '463ef4087b9200cd44b00c185324412baf15740091a240e7fb4f7923c99c88ec' 
  AND token = '+dza9nqF1MXvdhFsRLykF2xAdv0U5CXqsUejcn36r/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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