SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb113df5dc7fdfa7db0c65086d7c32022c1bc5a1a45a9fa1891fc5ca75d44255' 
  AND token = 'ciw+mKwYQpryRhN9alcCog4H9zlBjmthgXy78Ze2/kY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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