SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a26e4456db66add307dd0e0459860b8813900ff9b5bf809ed3ed286b20d7e40' 
  AND token = '+GRwWWk0Aj9IJ6cSWuEjnSbLopOS7vTieziBnux5i8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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