SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45e049fe1a8027ffd237f98716d30d3fcd548dbbe80c6c25b5479363f28f8af9' 
  AND token = 'ZB9mi+WZ5g9w9AspnSOi/qTguZWptloD2513OZGOhSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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