SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8442cec36299f012dbe705abb2b009413723abf17662b2a20d5fbc5d8c946914' 
  AND token = 'uCqgoBQdSAobkUXKefcYbaDyBvFsKZJhYT8kKYg5D7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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