SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e678240f7eac85d3001f2de2850e811c3a146ed1c494f3a2fcfb7e974c252ce' 
  AND token = 'BxgrvT6FZayDzhhpUJrMmrTXuJ5QO0RCEghGaKvmgWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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