SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea5c11c15935bce97e1be4a9a048a31668f1d5d920d35d1160f2635a45fea93c' 
  AND token = 'EuMnPfFlKg0qs+mz4HqKpQsR8zyMYU06E1OkYqjEY0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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