SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24edb536c7e23cdce0f04134a039843f63ebbddecbecc1f40a9cc499b9207464' 
  AND token = 'shDH71U+BYGqLThVUpY5scJroexa427SXe+Eg+vFdoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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