SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4672627264bbd9f4f61747fbbc51b483d94e07553d3199ffb14460a86a1e6247' 
  AND token = 'NyzK3Dx1/jJtpsqCD8oBy1kO8IJuGiJwDz38KIqTtmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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