SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60c46ad51903dd88dbc43fd4a22d680398b7cc84e2bcf2364eb7c8635b681b91' 
  AND token = '04wEXe8hCO1HSzu3b/UQd99rYSts23HMjskiLMUNNn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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