SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a529c458953949062b139e33fa4b72e21296e1f51aaeb2bac687e3afc2bbc12' 
  AND token = 'LzZKLUnks9xCJybyEPOjTGxLCQ1k1yRmaO8hAJ7kBf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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