SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd03e8ad89d0a071becf6ca84a32297f24a75700ef117f22288da1d16744fd73e' 
  AND token = 'vF2d3PrAMZiKZpfTPZRrSwEexZ2VwVFKAfWvVCzO2so=' 
  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"
    }
  }
}