SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20ead744c75554a87ca1bb7254f4fd1c09963ceca86d7fac8a4d28d1689956de' 
  AND token = '7/u4PMteZs99qCxPTsjYkfvBmdYwEIGjX1+OlAfLvyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}