SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10528e5ebd8c31ab31dace03cc4598261e3ebb3a949497bff249748f0988aaed' 
  AND token = 'ugT+8kX3WZzb4GmrWjlqZ45kQYYRCFNqoHZJl/Uo2Z8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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