SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6b035db6f8de9ab2fdf024b30202ab8c3f1ff2dfbed2f0ae093dfa9f57aa612' 
  AND token = 'fXhk5fMwafujlhwpfshRCPdJyoEzGpRQEQZJzZCqInM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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