SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89a05a84d5f52a4023a5c669f693d942a76533a7fb694d46c2c57e953ebee725' 
  AND token = 'jjjofLlTBPV4XKwvceoXUkyB+F4qp4EPGSlNtqNmjTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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