SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ad60e63465bcbaa559465fdbe93e44361f93e7bac95b7ab31932ad140d85fb9' 
  AND token = 'vFNR1KOxUhUFvkJXOF/Qb7KhYyVhiZEvVBd3IRnRM8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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