SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac94a959646a719a8d27bcb59ab9f92eb7ef384cf7a2dfe043899a2f73f853a' 
  AND token = 'f1L+ctCpryqhFCOzzUjjyVBK4aJg+soCDWvlFOWlAtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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