SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f421ec3da332da92a0af089dfbca9480c9e7ce5b7dce27b825c60117e20e06da' 
  AND token = 'xpjmylqv7jfUa/Er2YH2RdPUnLOfG873BkYawxZxMiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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