SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1506686cac6b704d834d6c2cf4b4ed606eef3e0df6c115cf751116ed5b283384' 
  AND token = 'ShvD3kRYEGuqiJaiuaRkhGkRF1GSIFMCAAxLuTV5MRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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